2. 4 Wireless Technology

3. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Objectives  Explain the principles of radio wave transmission.  Identify the major antenna styles.  Explain three transmission techniques used in radio wave-based transmission.  Recall the characteristics of the U-NII classifications.  Recall the key characteristics of the IEEE 802.11 wireless networking standards.  Explain the CSMA/CA access method.

4. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Objectives  Recall the key characteristics of the Bluetooth standard.  Explain how cellular technology works.  Compare the two types of microwave networks.  Compare the two types of infrared transmission.  Summarize the advantages and disadvantages of wireless networking.  Recall the purpose of the SSID.  Give examples of how security is provided in wireless networks.

5. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Wireless Media  Referred to as unbounded mediaunbounded media  Spread throughout atmosphere  Not limited to a single path Electronic signal Media type General classification WirelessAtmosphere Radio waves InfraredMicrowave

6. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Electromagnetic Waves  Categorized according to frequency ranges  Frequency is based on repeating pattern of waveform  One complete waveform is a cycle  Frequency is the number of times a cycle occurs in one second

7. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Radio and Microwave Transmission  Carrier wave is identified by a frequency number. Example: 104.5FM represents 104.5 MHz. Carrier wave  Modulation occurs before transmission, and is how AM and FM radio, and TV operate Modulation  Radio broadcast consists of transmitter and receiver, which must be near same carrier wave frequencytransmitter receiver  Human voice is converted into electrical energy  Electrical energy is mixed with carrier wave so voice can be transmitted

8. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Radio and Microwave Transmission (Cont.)  Demodulation occurs after carrier wave and voice wave are received Demodulation  Channel is identified by the assigned frequency Channel

9. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Voice Wave Broadcast

10. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Infrared Transmission  Uses a series of digital light pulses  Television remote control  Personal digital assistants  Laptops  Disadvantages  Devices must be in direct line of sight of each other  Can be used only for short distances

11. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Radio Interference  Can be caused by:  Virtually any type of electrical equipment  Faulty electrical equipment  Close proximity  A powerful signal  Industrial, Scientific, and Medical (ISM) band(ISM) band

12. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. ISM Band

13. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Signal Reflection  A reflected radio signal can combine with the intended radio signal and either disrupt the intended signal or enhance it

14. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Antenna Styles  The two major classifications are omni-directional and directionalomni-directionaldirectional ClassificationDescriptionRelated Antenna Styles Omni- directional Transmits electromagnetic signals in all directions Omni DirectionalTransmits electromagnetic signals in a focused or aimed direction Dipole Yagi Flat panel Parabolic

15. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Antenna Styles (Cont.)

16. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Radio Waves and Networks  Radio waves used in LANs Radio waves  Adhere to IEEE 802.11 and Bluetooth standards  Operate at 2.4GHz

17. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Radio Wave-Based Transmission Techniques  Spread spectrum refers to transmission channels spread across the spectrum of available bandwidth Spread spectrum  Frequency hopping Frequency hopping  Direct sequencing Direct sequencing  Orthogonal frequency-division multiplexing (OFDM) communicates wireless data over several different channels within an assigned frequency range Orthogonal frequency-division multiplexing (OFDM)

18. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Frequency Hopping Spread Spectrum (FHSS)

19. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Direct Sequencing Spread Spectrum (DSSS)

20. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Orthogonal Frequency-Division Multiplexing (OFDM)

21. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. FCC U-NII Classifications  FCC divided the 5 GHz radio frequency into three, 20-MHz channels called the Unlicensed National Information (U- NII) Infrastructure  Each U-NII classification has a frequency range of 100 MHz ClassificationFrequency Range U-NII 15.15 GHz –5.25 GHz U-NII 25.25 –5.35 GHz U-NII 35.75 GHz –5.825 GHz

22. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Radio Wave-Based Networking  Wireless Access Point (WAP) provides access to hardwired devices such as printers and routers Wireless Access Point (WAP)  WAP controls flow of communication  All WAPs use same Service Set Identifier (SSID)  SSIDs should be changed to enhance security

23. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Wireless Network Modes  Infrastructure mode Infrastructure mode  Ad hoc mode Ad hoc mode  IEEE 802.11 Standard uses terms Basic Service Set (BSS) and Independent Basic Service Set (IBSS)Basic Service Set (BSS)Independent Basic Service Set (IBSS)  Extended Service Set Identifier (ESSID) allows user to keep connection while moving around the location Extended Service Set Identifier (ESSID)  Devices need to be Wi-Fi compliantWi-Fi

24. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. IEEE 802.11 Standards IEEE Classification Assigned FrequencyMaximum Data Rate Transmission Method 802.11a5 GHz54 MbpsOFDM 802.11b2.4 GHz11 MbpsDSSS 802.11g2.4 GHz 5 GHz 11 Mbps (802.11b mode) 54 Mbps (802.11g mode) DSSS OFDM 802.11n2.4 GHz 5 GHz 54 Mbps (802.11a mode) 11 Mbps (802.11b mode) 54 Mbps (802.11g mode) 300 Mbps (802.11n mode) OFDM

25. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. You are replacing a dead 802.11g WAP in an existing wireless network with an 802.11n WAP. Three laptops connect to this network. Two have 802.11n wireless adapters, and one has an 802.11g adapter. What will the maximum data rate be when the 802.11n WAP is installed? Applied Networking

26. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. 802.11n  Latest 802.11 wireless network topology  Multiple Input Multiple Output (MIMO) Multiple Input Multiple Output (MIMO)  MIMO increases data transmission rate by using spatial multiplexing spatial multiplexing  Prior to MIMO, WAPs sent single stream of data between transmitter and receiver

27. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. CSMA/CA Process

28. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Overlap Area  Ad-hoc overlap area  Infrastructure mode overlap area

29. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Extending Wireless Network Range with WAPs

30. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Extending Wireless Network Range with Cabling

31. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. You’ve been asked to create an Extended Service Set (ESSID) from two existing 802.11 g wireless networks. However, the two WAPs (one from each network) are about 75 meters apart. How can you extend the range without adding another WAP? Applied Networking

32. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. New IEEE Wireless Standards  Working group—Standards that are still under development Working group  Also known as Wireless Personal Network (WPAN)Wireless Personal Network (WPAN)  IEEE 802.16 is working group hoping to:  Achieve data rates as high as 70 Mbps over distances of 30 miles or more  Expand the radio frequencies assigned by the FCC

33. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. New IEEE Wireless Standards (Cont.)  Wireless USB connects devices wirelessly to transfer data between a PC and devices such as cameras, printers, and mobile phones, among others  Bluetooth, or piconetpiconet  Short-range wireless system designed for limited distances  Does not interfere with 802.11b devices

34. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Cellular Technology  Device connects to radio transmitter/receiver within its cell  Communicates to remote cells via microwaves  Responsible for wireless telephone technology  Connects mobile and stationary computer equipment

35. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. PC to Mobile Network Device Cellular Communication

36. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Microwave Transmission and Networking  Microwave describes radio waves in the electromagnetic spectrum  Higher radio wave frequency=more data transmitted  Satellite travels in a geosynchronous orbitgeosynchronous orbit  Significant disadvantage of satellite communications is propagation delaypropagation delay

37. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Satellite System

38. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Wireless Technology AdvantagesDisadvantages Cost-effective compared to cable-based network media Easy to install Appropriate for mobile devices Affected to various degrees by atmospheric conditions Security because wireless transmissions can be intercepted

39. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Wireless Security  IEEE 802.1x draft standard for wireless network  Extensible Authentication Protocol (EAP) uses exchange of username and password Extensible Authentication Protocol (EAP)  PEAP is improved version of EAP  Wired Equivalent Privacy (WEP) uses encryption keys to secure data sent over wireless networks Wired Equivalent Privacy (WEP)

40. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Wireless Security (Cont.)  Wi-Fi Protected Access (WPA) Wi-Fi Protected Access (WPA)  WPA-PSK is variation of WPA  WPA-2 is improved version of WPA  Wireless Application Protocol (WAP) combines authentication and encryption Wireless Application Protocol (WAP)

41. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. IEEE 802.1x Authentication and Encryption Protocols IEEE 802.1x AuthenticationIEEE 802.1x Encryption Extensible Authentication Protocol (EAP) Wired Equivalent Privacy (WEP) Protected EAP (PEAP)Wi-Fi Protected Access (WPA) Wi-Fi Protected Access-Pre- Shared Key (WPA-PSK) Wi-Fi Protected Access 2 (WPA-2) Wi-Fi Protected Access (WAP)

42. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Windows XP WLAN Properties

43. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Windows Vista Wireless Network Properties

44. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. When configuring a Wireless Access Point for a home network, the installation program prompts you for a security type. The choices are WPA2- Enterprise, WPA-Personal, and WEP-128. Which security type would be the most appropriate for the given wireless network, while providing the highest level of security? Applied Networking

45. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.  Ad hoc mode  A wireless network that does not contain a Wireless Access Point.  Basic Service Set (BSS)  An IEEE term used to describe a group of wireless devices connected as an infrastructure network or an SSID.  Carrier wave  An electromagnetic wave of a set frequency that is used to carry data. Glossary

46. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.  Cellular technology  A technology based on radio waves connecting to designated areas referred to as cells.  Channel  The bandwidth of a carrier wave.  Demodulation  The process of separating a data signal from a carrier wave.  Direct sequencing  A spread spectrum technique that transmits data on multiple channels sequentially. Glossary

47. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.  Directional  The ability of an antenna to transmit electromagnetic signals in a focused or aimed direction.  Extended Service Set Identifier (ESSID)  Two or more Wireless Access Points or wireless devices using the same SSID.  Extensible Authentication Protocol (EAP)  A protocol that ensures authorized access to the network system and network resources. It is used on both wired and wireless network systems. Glossary

48. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.  Frequency hopping  A spread spectrum technique that transmits data on multiple channels simultaneously.  Geosynchronous orbit  An orbit in which a satellite’s rotational speed is synchronized with the earth’s rotational speed, making the satellite appear to be in a stationary position.  Independent Basic Service Set (IBSS)  A network that does not use an access point and usually is a direct connection between two wireless devices. Glossary

49. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.  Infrastructure mode  A wireless network that contains one or more Wireless Access Points.  ISM band  The band of radio frequencies associated with industrial, scientific, and medical devices.  Modulation  The process of mixing a data signal with a carrier wave. Glossary

50. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.  Multiple Input Multiple Output (MIMO)  A wireless networking technology that transmits two or more streams of data to increase data throughput and the range of the wireless network.  Omni-directional  The ability of an antenna to transmit electromagnetic signals in all directions. Glossary

51. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.  Orthogonal frequency-division multiplexing (OFDM)  A transmission technique that transmits data over different channels within an assigned frequency range. Each channel is broadcast separately and is referred to as multiplexed. It can achieve data rates as high as 54 Mbps.  Piconet  A Bluetooth network. Also called a Personal Area Network (PAN).  Propagation delay  The time it takes for data to be transmitted from the earth and satellite. Glossary

52. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.  Radio interference  Interference that matches the frequency of a carrier wave.  Radio waves  Electromagnetic waves with a frequency range of 10 kHz to 3,000,000 MHz.  Receiver  An electronic device that receives a modulated signal and demodulates it.  Spatial multiplexing  A wireless networking technology that transmits two or more streams of data in the same frequency channel. Glossary

53. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.  Spread spectrum  A transmission technique that uses multiple channels to transmit data either simultaneously or sequentially.  Transmitter  An electronic device that generates a carrier wave and modulates the data signal into the carrier wave.  Unbounded media  An unrestricted path for network transmissions. Glossary

54. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.  Wi-Fi Protected Access (WPA)  A protocol that combines the authentication method with encryption.  Wi-Fi  A term coined by the Wi-Fi Alliance that refers to 802.11 wireless network products.  Wired Equivalent Privacy (WEP)  A data encryption protocol that makes a wireless network as secure as a wired network. Glossary

55. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.  Wireless Access Point (WAP)  A wireless network device that provides a connection between a wireless network and a cable- based network and controls the flow of all packets on the wireless network.  Wireless Application Protocol (WAP)  A protocol that ensures the safe exchange of data between a wireless network and a portable Wi-Fi device, such as a cell phone. It uses a set of keys to identify a device and to encrypt the data exchanged. Glossary

56. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.  Wireless Personal Area Networks (WPAN)  A small Ethernet network consisting of personal wireless devices such as a cell phone, laptop, palmtop, wireless printer, Wireless Access Point, iPod, Xbox 360, and similar items.  Working group  A standard not fully developed and adopted as an official standard recognized by IEEE. Glossary